Critical Study on Scratch Resistance Test Methods
A number of international test methods have been advanced in various industries – electronics, optical, automotive and others – to evaluate the scratch resistance (abrasive wear) of thin film UV-curable coatings on polymeric substrates, displays and qualify coatings suppliers. Some of these wear tests do not provide valid inferences with real life experiences and pose a conundrum on the proper evaluation of different coatings performance on thermoplastic and transparent substrates.
This paper will address different scratch resistance tests – focusing on abrasion wear, – the Taber® Abraser, Norman Tool “RCA”, Pencil Hardness and Steel Wool Wear tests on Polycarbonate (PC) and Poly Methyl Methacrylate (PMMA) optical clear, thermoplastic sheet materials with two sample UV curable coatings, under 15 μm in dry film thickness.
Conclusions and recommendations on the practical selection and use of various wear tests to ascertain the abrasion resistance of UV-curable thin film coatings will be discussed.